Chris Mason: Rwanda bill a reminder of Brexit Tory divisions

It had been a while since I'd heard mention of a "Star Chamber".

But it is back in the lingo of Westminster.

This weekend different groupings of Conservative MPs are scrutinising the government's planned new law on the Rwanda migrants plan.

It will come to a vote on Tuesday.

It is provoking flashbacks for me of the Brexit years, where deep, wide, passionate and angry arguments within the Conservative Party dominated.

Enter next, a grouping of that era, the Conservative European Research Group.

During the Brexit debates, they sought to ensure ministers remained committed to what they saw as a proper Brexit, leaving all the main structures of the EU and not diluted compromise.

Its chairman, Mark Francois said: "We all agree with the prime minister that we need to stop the boats but the legislation to do this must be assuredly fit for purpose.

"To that end, I spoke with Sir Bill Cash this morning, who confirmed that his Star Chamber Team are already analysing the Rwanda Bill, in detail.

"This may still take a few days to complete but he was confident their findings will be available, at the very latest, prior to the Second Reading debate on Tuesday."

There you have it, the Star Chamber of legal experts chaired by Sir Bill is back.

It will want to test the instincts of the former Home Secretary Suella Braverman and the former immigration minister Robert Jenrick who have both concluded the Rwanda Bill is a dud.

Other groupings of different instincts have similar approaches.

A leading member of the so-called One Nation caucus of Conservative MPs told the BBC a decision on whether to vote for, against, or abstain on the Rwanda bill will not be taken until Monday evening's meeting of the group.

However, he described the mood generally as one of "deep concern".

They are taking legal advice from the former Solicitor General Lord Garnier, who told Radio 4's PM programme he'd vote against the bill in the Lords, and that declaring in law that Rwanda was safe was rather like declaring "all dogs are cats".

But here's another twist: These groups are not homogenous and those who appear on their behalf don't represent the views of all of their members.

So where does all this leave Rishi Sunak?

Being at the mercy of clumps of your own backbenchers is never a comfortable place for any prime minister to be in.

Plenty of Tory MPs now think it is entirely possible a sufficient number of their colleagues will register a loss of confidence in Mr Sunak that he faces a vote of confidence.

In all likelihood he would win such a vote, but it even happening would be crippling to his authority.

Let's be clear: It may well not happen.

But a range of folk with a deep knowledge of the parliamentary party think it could.

Oh and one final thought.

Before that moment on Tuesday, Mr Sunak has another big moment on Monday: Appearing at the Covid inquiry.